JE Pistons Ultra Series GM Gen III/IV LS 4.125in Bore/4in Stroke Set of 8 Pistons

If you're building a serious GM Gen III or IV LS engine, especially one that's going to see boost or nitrous, you need pistons that can handle the pressure. These Ultra Series forged pistons from JE Pistons are built for exactly that. They're designed to withstand the extreme cylinder pressures that come with power-adder builds, offering a robust foundation for your high-horsepower V8.

What sets these pistons apart is JE's proprietary Aligned Grain Flow forging technology. This in-house process maximizes the material's tensile strength, making them incredibly strong. On top of that, they come with custom-level features you'd normally only find on fully custom pistons. You get a thermal barrier crown coating that reflects heat back into the combustion chamber, helping to keep temperatures down and improve how the exhaust gases are scavenged. The skirt coating is there to reduce friction and wear on the piston skirts and cylinder walls, which also helps quiet things down, especially when the engine is cold. Plus, they have lateral gas ports to help maintain a solid ring seal even at high RPMs and under heavy boost, ensuring consistent power delivery. They also feature optimized pin oiling for better lubrication and come with high-strength wrist pins from Trend Performance, built for the demands of serious performance engines.

These pistons are made 100% in the USA, ensuring solid construction. Keep in mind they are not CARB approved, so they cannot be shipped to California. If you're aiming for a powerful, reliable LS engine build, these pistons are a well-built choice.